Strategies to Increase Attendance in Harm Reduction Substance Use Disorder Interventions in Disinvested and Predominantly Black Urban Communities

Background: Alcohol and/or substance use (ASU) among residents of disinvested and predominantly Black communities is associated with harsher consequences (e.g., higher incarceration) compared to those experienced by their White and wealthier counterparts. Due to systemic barriers, these individuals face greater challenges in engaging with treatment services. Offering financial incentives to attend, providing flexibility in group structures, and engaging individuals under surveillance (e.g. in drug court) may enhance participation.

Methods: This study followed Community Based Participatory Research (CBPR) principles to conduct a 2³ factorial randomized experiment designed to identify active components that increase attendance in a substance-use-disorder (SUD) intervention using a sample of 166 people with a history of SUD. Candidate intervention components included (1) Payment (receiving $20 to attend group sessions versus not receiving payment), (2) Surveillance (participating in methadone, drug court, probation, or parole versus not), and (3) Group Delivery (open group versus closed group). Outcome was number of people attending at least 50% of sessions (range= 0-8) recorded weekly by a peer facilitator. Participants were recruited using street outreach and facility-based sampling. Participants completed a baseline survey, and a 3-month follow-up survey online using RedCap. Baseline and follow-up included the Treatment Services Review, the Timeline Follow Back, and demographics. Assessment took 30 minutes to complete. Participants received $20 to complete baseline and $30 to complete follow-up assessment. Intervention attendance was recorded weekly in RedCAP by the peer facilitator. We conducted logistic regressions to examine the odds of participants attending over 50% of sessions across intervention components. We conducted generalized linear modeling analysis for the outcome of ASM at follow-up adjusting for baseline ASM and demographic factors. Finally, we used mediation analysis to test the mediating effect of intervention components on session attendance and ASM.

Results: Most participants were male (70%), Black (76.8%), never married (68.3%), and unemployed (84%) with a mean age of 43 (SD + 11.7) and mean annual income of $7,525.99 (SD +13,356.22). Participants attended an average of 3 sessions (SD + 3.2). At baseline, participants reported using alcohol, heroin, cocaine, and/or alcohol an average of 16 days in the past 30 days (SD + 8.6). Intent-to-treat analysis showed that receiving payment we found that paying participants to attend sessions (OR= -0.68, p=.004) and being under surveillance (OR=0.49, p=.036) produced statistically and clinically significant main effects in attending at least 50% of the sessions. Participation in open groups had a significant synergistic effect when participants were paid to attend the sessions. Per the multiphase optimization strategy framework, we conclude that paying participants to attend open groups is the optimal engagement strategy to increase attendance in at least 50% of sessions. Higher attendance resulted in lower ASM (β =-.30; p=.010) while paying participants to attend sessions had no effect on ASM (β=-0.03; p=.933).

Conclusions: Findings supported our original hypothesis that paying participants to attend open groups significantly increase attendance which in turn reduced ASM. Future research will examine test the optimized intervention against standard of care in a randomized-controlled-trial.